Collimation testing of laser beam with holographic optical elements

The shear elements in the shear interferometers of collimation test are commonly plane parallel plates or wedge plates of a small wedge angle. A new holographic shear element that acts as the wedge plate is proposed. The interferometer composed of holographic shear lenses has the advantages of high contrast fringes and adjustable shear amount. It posses the flexibility of altering the measurement sensitivity in a broad range, has more suitability and can meet different measuring requirements. Detailed analysis for the experimental configuration of this system is presented.

► A new holographic shear element is proposed.
► The interferometer based on the shear element is constructed for collimation test.
► It has the advantages of high contrast fringes and adjustable shear amount.
► The sensitivity can be conveniently controlled by choice of the shear amount.